中文摘要：

通过室内模拟降雨试验，研究了坡度对粘性红壤土坡面产流产沙、溶质运移特征的影响。结果表明，不同坡度红壤土坡面径流强度随时间均呈线性变化关系；径流总量随着坡度增大呈线性递减关系。径流泥沙流失量随着坡度增大呈先增加后减少的变化趋势，红壤土坡面侵蚀产沙存在着临界坡度。坡度对溴离子流失过程影响较小，径流溴离子质量浓度随时间变化均呈幂函数衰减过程。降雨停止后溴离子淋溶深度随着坡度增大而增大，速效磷集中分布在表层5cm土层内。坡度15°左右为红壤土坡面径流溶质流失最少的临界坡度。

英文摘要：

The effect of gradient on runoff process and solute transport characteristic for red soil slope was investigated by using simulated rainfall experiments indoor. Results showed that the variations of runoff rate with time under different gradients for red soil slopes were described by linear functions. Total volume of runoff decreased linearly with the increase of gradient. There was a critical slope gradient for red soil erosion process according to the relationship between the sediment loss and slope gradient. The decay processes of Bromine concentrations in runoff were well described by a power function for different slope gradients. The Brleaching depth in soil profile increased with the increase of slope and the soil extracted phosphorous distributed mainly in the soil profile of 5 em in depth after simulating rainfall. It could be determined preliminarily that the critical slope gradient for the least loss of solution was approximate 15° according to the relationship between solution loss and gradients.